Regional Anatomy of Upper Limb

Pectoral & Shoulder Region

Dr. Kumar K.VAssociate Professor

Parts and regions

• Shoulder region: junction of arm and trunk

• Arm: between shoulder and elbow

• Elbow: bend of arm, joint between arm and forearm

• Forearm: between elbow and hand

• Hand

Pectoralis major• Origin: medial half of

clavicle,sternum,1th-6th costal cartilages.

• Insertion: crest of greater tubercle of humerus.

• Action: flexes, adducts and rotates arm medially; arm fixed, elevates trunk; elevates ribs 1-6,helping in forced inspiration.

The muscles of thorax

Extrinsic muscles• Pectoralis major• Pectoralis minor • Serratus anterior

Intrinsic muscles• Intercostales externi

• Intercostales interni

• Intercostales intimi

Deltoid

Mammary Gland

Position• Lie in superficial

fascia over the pectorals major and pectoral fascia

• Extend from 3rd to 7th ribs vertically, and from parasternal line to midaxillary line transversally

Structures contains skin, mammary glands and adipose tissue

• Each breast has about 15-20 lobes of mammary gland

• Each lobe radiates out from the nipple and has a lactiferous duct, which opens separately on the summit of the nipple and possesses a dilated lactiferous sinuses just prior to its termination

• Suspensory ligaments of breast(cooper’s ligaments):strands of connective tissue runs between skin and deep fascia and serve to support the mammary glands

Suspensory ligaments

Axilla

• The axillary fossa is a pyramid-shaped space through which major neurovascular structures pass between the thorax and upper extremity

Boundaries • The apex is a

triangular space limited by the first rib, the scapula, and the middle third of clavicle.

• The base: skin and fascia of the axillary fossa

• The broad medial wall: serratus anterior: intercostal muscles and upper four ribs

• The narrow lateral wall: coracobrachialis, biceps brachii and intertubercular groove

Contents Brachial plexus, axillary a. and principal branches, axillary v.

and tributaries, axillary lymph nodes and loose connective tissue

Axilla as seen from aboveLateral View

• The anterior wall– Pectoralis major, pectoralis minor and subclavius muscles– Clavipectoral fascia

• The deep faxcia which extends between subclavius, coracoid process and pectoralis minor muscles

• The structures pass through the clavipectoral faxcia– Cephalic v.– Thoracoacromial a.– Lateral pectoral n.

• The posterior wall: teres major, latissimus dorsi, subscapularis and scapula

Trilateral and quadrilateral foramina

• Between the subscapularis and teres major, there is a long triangular space whose lateral side is surgical neck of humerus. The long head of triceps brachii subdivides this space into a medial trilateral foramen and a lateral quadrilateral foramen.

• The posterior humeral circumflex a. and axillary n. pass through the quadrilateral foramen.

• The circumflex scapular a. passes through the triangular space to reach the dorsum of the scapula.

Brachial plexus Formation:• Five roots: formed by anterior rami of

C5-C8 and T1 spinal nerves, roots C5 ～ C7give rise to long thoracic n.

• Three trunks– The upper trunk is formed by the

joining of root C4,C5,C6.– The middle trunk is the continuation of

root C7.– The lower trunk is formed by the joining

of root C8 and T1.• Six divisions: above clavicle, trunks

form anterior and posterior divisions• Three cords: below clavicle, divisions

form three cords that surround the second portion of axillary a.

Ventral Rami of Spinal Nerve

Dorsal Root

Ventral Root

spinal nerve

Dorsal Ramus of spinal nerve

Ventral Ramus of spinal nerve

Parts of Brachial Plexus

• Really Tired? Drink Coffee Boys!

• R = ROOTS (ventral rami)

• T = TRUNKS

• D = DIVISIONS

• C = CORDS

• B = BRANCHES

Axillary artery

• Continuation of subclavian artery at lateral border of first rib

• Becomes brachial artery at lower border of teres major

• Divided into three parts by overlying pectoralis minor

– First portion, above muscle － gives rise to thoracoacromial a.

– Second portion, behind muscle － gives rise to lateral thoracic a.

– Third portion, below muscle － gives rise to subscapular a. , anterior and posterior humeral circumflex a. ; the former then divides into throcodorsal a. and circumflex scapular a.

Veins

•Cephalic (arm-forearm)•Basilic (arm-forearm)

•Median Cubital (elbow)•Median Vein

•SF. Palmar Venous Arch•Digital

SUPERFICIAL

•Subclavian (neck)•Axillary (axilla)

•Brachial (arm-elbow)

•Radial (forearm)•Ulnar (forearm)•Deep Palmous Venous arch

DEEP

Axillary lymph node － arranged in five groups• Lateral lymph nodes － lie around the distal

end of axillary artery vein , receive afferent vessels from upper limb.

• Pectoral lymph nodes － lie along lateral thoracic vessels, receive afferents from anterior thoracic wall including central and lateral portion of mamma

• Subscapular lymph node － along subscapular vessels, receive lymph from nape and scapular region

• Efferents above three groups pass to central lymph node

• Central lymph node － lie in fat of axillary fossa, receive lymph from all the above nodes, efferents pass to apical lymph node

• Apical lymph node － lie in the apex of the axilla, along the proximal end of axillary vessels, receive afferents chiefly from central lymph node , upper portion of mamma; efferents form subclavian trunk, the right subclavian trunk joints the right lymphatic duct; left usually drains directly into thoracic duct

Major muscles of the trunkTrapezius • Origin: superior nuchal line,

external occipital protuberance, ligamentum nuchae and spinous processes of seventh cervical and all thoracic vertebrae

• Insertion: lateral third of clavicle, acromion, and spine of scapula

• Acton: upper fibers elevate scapula, lower fibers depress scapula; if scapula is fixed, one side acting along, draws head toward the same side, and turn face to opposite side; both sides together, draw head directly backward

Latissimus dorsi• Origin: spinous

processes of lower six thoracic and all lumbar vertebrae, median sacral crest, and posterior part of iliac crest.

• Insertion: floor of intertubercular groove of humerus.

• Action: trunk fixed, extends, adducts and medially rotates arm ; arm fixed, elevates trunk.

The Muscles of Upper Limb

Muscles of shoulder• Deltoid• Supraspinatus• Infraspinatus• Teres minor• Teres major• Subscapularis

Muscles of arm• Anterior group

– Biceps brachii– Coracobrachialis– Brachialis

• Posterior group

– triceps brachii

Teres major• Origin: dorsal

surface of inferior angle of scapula

• Insertion: crest of lesser tubercle of humerus

• Action: medially rotates and adducts arm